Improvement in drawing-tables



2Sheets --Sheet i.- JOSEPH L. ROSS & FREDERIC C HANSON.

Improvement in Drawing Tables.

No. 122,134. Patentd Dec. 26, 1871.

' 2Sheets--8heet 2. I

JOSEPH L. ROSS 8L FREDERIC C. HANSON.

plmprover nent in Drawing Tables.

No. 122,134; Patented Dec. 26, I871.

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a circular plate,

@ATES JOSEPH L. ROSS, OF BOSTON, AND FREDERICK O. HANSON, OFGHARLESTOWN,

. MASSACHUSETTS.

IMPROVEMENT lN DRAWING-TABLES.

Specification forming part of Letters Patent No. 122,134, dated December26, 1871.

To all whom it may concern:

Be it known that we, JosEPH L. Ross, of Boston, in. the county ofSuffolk and State of Massachusetts, and FREDERICK GJHANsOrI, ofOharlestown. in the county of Middlesex' and State aforesaid, haveinvented certain Improvements in DrawingBoards for Architects,Engineers, Schools, &c.; and we hereby declare the following to be afull, clear,- and exact description of the same, reference being had tothe accompanying drawing making part of this specification, in which-Figure 1 is a perspective view of a drawingboard constructed inaccordance with our invention. Fig. 2 is a vertical section through thecenter of the same. Fig. 3 is a transverse section 'on the line a: or ofFig. 2; Fig. 4., detail to be referred to.

Our invention consists in a drawing-board provided with a screw'shaft,which is revolved by operating ascrew wheel, in order to raise or lowerthe board to any required height. And our invention also consists in astand or holder for supporting the object to be drawn, or for holding alight, the stand or holder, when adjusted to any required height, beingclamped securely in place.

Our invention also consists in securing to the under side of thedrawing-board a plate, which is clamped to a plate secured to the top ofthe screw-shaft; oueof the plates beingprovided with a slot, and theother with a screw-pin, which enters the slot to admit of a screw nutbeing used to tighten the plates together, thus producing sufficientfriction to keep the board at any desired inclination.

To enable others skilled in the'art to understand and use our invention,we will proceed to describe the manner in which We have carried it 7out.

Inthe said drawing, A is the tripod, from which rises the verticalstandard 13, longitudinally through the center of which is formed acircular hole a, for the reception of a vertical screw-shaft, whichmoves loosely therein, first passing through a screw-wheel, D resting onthe top of the standard. Secured to or forming a.

part of the top of the screw-shaft is a circular plate, E, secured tothe board, and to which is pivoted at 1) another plate, F, a portion ofwhich is of similar form thereto, having near its periphcry a slot, 0,the sides of which are parallel to each other, and concentric with theperiphery. The upper portion of the plate E terminates in d, the planeof whose surface is at right angles to that of the lowerportion of theplate F. c is a screw-pin, fastened to and passing through the plate Enear its periphery; this pin projects into and through the slot cl, andreceives a screw-nut', f, Fig. 4, which, when tight,

ened down on the plate F, clamps it firmly against the plate E, andkeeps the board at any inclination to which it may have been adjusted. Gis a collar set into the standard for the screw-shaft to pass through,thediameter of the interior of the collar being slightly larger thanthat of the shaft. Formed in one and the same piece with the collar is ascrew-pin, h, which projects outside the standard and receives ascrew-nut, i, which is clamped against the side of the standard so as tobring the opposite interior surface of the collar tightly against thescrew-shaft, thus keeping it from descending and holding the board up tothe desired height. Secured to the outside of the standard at anyconvenient point is a projecting piece which forms a bearing, k, for theinner bent end of a horizontal rod or bar, H, the outer end of which isprovided with a hole for the reception of a long vertical rod, 1, to theupper end of which is secured the stand or holder K for the object orlight. Z is a screw, the point or end of which may be turned against therod Iso as to, clamp it and keep the stand supported at any desiredheight.

From the foregoing it will be seen that the board may be held steadilyin a horizontal position, or inclined to any desired angle, while, byrevolving the screw-shaft the height of the'board may be varied, and thework brought into the most convenient position for the draughtsman, theobject being swung around to be constantly before him. L is asliding-drawer, for holding the artists instruments and materials.

What we claim as our invention, and desire to secure by Letters Patent,as an improvementpin drawing-boards, is,

1. The adjustable holder K, in combination with a drawing-board,substantially as and for the purpose described.

2. The plate E attached to the top of the shaft 0, in combination withthe slotted plate F and screw-clamp e f, operating substantially in themanner and for the purpose set forth.

Witness our hands this 1st day of September A. I). 1870.

JOSEPH L. BOSS. FREDERICK C. HANSON.

Witnesses: v

P. E. TESCHEMACHER,

W. J. CAMBRIDGE. (97)

